Linux: Out-of-bounds Write
CVE-2024-27050 is a high-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions fa5bef5e80c6a3321b2b1a7070436f3bc5daf07c, 682ddd62abd4bdcee7584246903e7a2df005fe0d, cd3be9843247edb8fc6fcd8d8237cbce2bc19f5e as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.29% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to fa5bef5e80c6a3321b2b1a7070436f3bc5daf07c or 682ddd62abd4bdcee7584246903e7a2df005fe0d or cd3be9843247edb8fc6fcd8d8237cbce2bc19f5e or 92a871ab9fa59a74d013bc04f321026a057618e7, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 13ce2daa259a3bfbc9a5aeeee8b9a87058703731 up to, but not including, fa5bef5e80c6a3321b2b1a7070436f3bc5daf07c; 13ce2daa259a3bfbc9a5aeeee8b9a87058703731 up to, but not including, 682ddd62abd4bdcee7584246903e7a2df005fe0d; 13ce2daa259a3bfbc9a5aeeee8b9a87058703731 up to, but not including, cd3be9843247edb8fc6fcd8d8237cbce2bc19f5e; 13ce2daa259a3bfbc9a5aeeee8b9a87058703731 up to, but not including, 92a871ab9fa59a74d013bc04f321026a057618e7; 6.6 | fa5bef5e80c6a3321b2b1a7070436f3bc5daf07c, 682ddd62abd4bdcee7584246903e7a2df005fe0d, cd3be9843247edb8fc6fcd8d8237cbce2bc19f5e, 92a871ab9fa59a74d013bc04f321026a057618e7 |
| Linux | acrn | Not specified in the record | Not stated |
| Linux | linux_kernel | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 5.5 | Medium | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: libbpf: Use OPTS_SET() macro in bpf_xdp_query() When the feature_flags and xdp_zc_max_segs fields were added to the libbpf bpf_xdp_query_opts, the code writing them did not use the OPTS_SET() macro. This causes libbpf to write to those fields unconditionally, which means that programs compiled against an older version of libbpf (with a smaller size of the bpf_xdp_query_opts struct) will have its stack corrupted by libbpf writing out of bounds. The patch adding the feature_flags field has an early bail out if the feature_flags field is not part of the opts struct (via the OPTS_HAS) macro, but the patch adding xdp_zc_max_segs does not. For consistency, this fix just changes the assignments to both fields to use the OPTS_SET() macro.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Out-of-bounds Write vulnerabilities
- 7.5 High severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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